Automatic motor switch



'k Nov. 6 1923.

- T. o. PERRY AUTOMATIC MOTOR SWITCH 3 Sheets-Sheet 1 4 Filed June 30 Nov. 6 1923.

T. o. PERRY AUTOMATI C MOTOR SWITCH Y In \R 3 Sheets-Shee't 2 (TM C).

Filed June 30 Nov. 6, 1923.

1,473,441 T. O. PERRY AUTOMATIC MOTOR SWITCH Filed June 30, 1922 3 Shets-Sheet 5 Patented Nov. 6 H

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nurolvmrio oron swim 0H} 7 Application filed June so, 192;. Serial 115,572,075.

T 0 all whom it may concern r Be it known that I, THOMAS O. PERRY, a citizen of the United States, residingin Oak Park, in the county of Cook and State of: Illinois, have invented a new andusefu'l AUtOmELtICMOtOP Switch, of which the following is a specification. 7 1

My 'nvention relates to improvements inv motor switches which are required 'to automatically control the intermittent operation of a motor which actuates apump or aspirae tor for reducing or lncreasing air pressure, 1n a tank orsystem normally closed against admission of external air, so as to maintain within maximum and minimum' limits, ap-

proximately uniform tension due to the action of the pump. My inventio'n .is especially applicable to systemsinwhich water is an; essential medium for exhausting the air andj also anecessity of the system. The applica-I tion of my invention to. a vacuumvheatingg 20 whichjunite the two discs to' each other; The lower. disc 19 has ,a tubularjournali underneath which turns in; a suitable bear;

system is illustrated in the accompanying drawings,in'which a Fig. 1 is a sideelevation of the apparatus essential to operation of the. switch showing in section the, cistern and some parts which support the aspirator therein; Fig. 2, an inverted plan of the motor switch, represented as an ordinary knife switch suchas. is commonly used for control of electric motors; Fig. 3, a sectional plan of the submerged aspirator taken below the line 3'-3 on Figs. 1 r and 4; Fig; 4, a side elevation ofthe ap--;- 'paratus modified in form; Fig. 5, an'elevation of the modified switch viewed at right angles to its position shown in Fig. 1; Fig- 6, an enlarged sectional elevation of the modified switch pulley and its divided axle Fig. 7, a plan of the submerged bearing for the aspirator; and Fig. 8, a general outline.

in elevation to a reduced scale showing the application of my invention to avacuum,

through the main; The water of'condensa-. tion is supposed in this case to flow by gravitation back into the boiler. by way of the steam main 11. An ordinary air vent valve 1 is shown attached'to the radiator and is supposed to prevent or restrict es a e 5r steam but to allow air to; pass out freely; A n air-line suction pipe15 leads f rom the air, valve into the basement; or to anyfconvenient place for dlsposing ofany chance leakage otsteam past .the air valve. This Y is the. ordinary arrangement in simple steam heating systems. In .Our improvement the T suctionpipe 15 is carried into an o'penllow-i level cistern 16;locatedon or belowthebase Y iment floor; An overflow near thetop of the cistern serves for arry pipe 17 connected ing away surplus accumulation; o

The cistern is. supposed to be first-filledlwith water or some fluid up to the overflow connection and to constantly retainthat amount of fluid which can not escape. Theiaspi'ra opposite sides of the periphery by partitions tor fconsistswof two small discs 18 and .19 axially separated, as shown, and havingv the "Z5 cylindricalintervening space interrupted on e ingfcomposed of four pieces of wood 22 are 7 ranged radially andfastened upon a bearing plate 23 so that their inner ends unite closely to form the bearing at the center ,oi' the, bearing plate'as shown in, Fig.. 7. 'Thescrew holes 24 servefor fastening thejbearing plate 23uponthe larger supporting plate 25 which is suspend ed I from the cistern cover 26 by Imeansof; tubular posts 27 and inclosed- V suspension rods. 28. Four water brakes '29 are shown-fastened to'ithe wood bearings'22 and extending up above'the discsaround, whose, periphery they "are equally spaced without touching. gThese waterl brakes' serve to increase the eficiency 0fthe-aspirat0rby holding the submerging liquid against its,

tendency to rotate with the discs; The. lowerend of the air line'suction pipe 15 connects with the supporting plate 25 just below the tubular journal 21 as shown in Figs. 1 r and 4, The actuating motor 30, here rshown as of the vertical electric type, rests on the by means ofthe lntermediate aspiratorshaft 81. The vent holes 82 in the J cover 'allow submerging liquidby. the aspiratonz 5 shown in Fig. 1 as Qattachedfto a; ceiling board 33 which.inturn is supposed tobeatcistern cover 26 and "has its. shaftfdirectly connectedjwith the upperaspiratoradisc 181 1 05 free escape .ofithe air delivered. through tached to thebasement ceiling. [The i 1 34 of the switch is shown pushed up to the closed circuit position and its is indicated by dotted lines. A link 35 pivotally connects the switch blade with the actuating lever 36 fulcrumed at one end to the bracket 37 depending from the ceiling board 33. The other end of the actuating lever eX- tends some distance horizontally and carries a liquid chamber 38 whose weight and that of the lever is overbalanced by the counterweight 39. This counterweight 39 could have been directly applied by extending the lever both ways beyond the fulcrum, but is here shown as suspended by a'cord 40 which runs over a ceiling pulley 41 and down to a screw eye connection 42 with the end of the lever as shown. The liquid chamber 38. rests on the lever 36 and its cylindrical body 43 is preferably made of glass. The body 43 is clamped between upper and lower enclosing heads 44 and 45 by means of the binding rod 46 whose lower end extends down through the lever with a nut beneath. A supply pipe 47 connects withthe lower enclosing head 45 of the chamber 38 and extends along the under side of the lever 36 to a point near the fulcrum where'a short flexible tube 48 is inserted to join with the vertical pipe 49 which extends some distance downward into the liquid within the lowlevel cistern 16. A suction tube 50 connects with the upper inclosing head 44 of the chamber38 and is carried along the upper surface of the actuating lever, connecting near the fulcrum with the air line' suction pipe 15 by means of a short flexible'tube 51. The flexible tube connections 48 and 51 permit the actuating lever to swing about its fulcrum as required to make and break electrical connection with the motor by means of the switch blade 34. The binding screws 52 connect with the main and return wires of the electric current supply. 'The binding screws 53 are supposed to connect with the wires 54 which supply the motor 30. The switch parts are mounted on an insulating base 55 attached to the ceiling board 33.

The operation is as follows: VV'ith the motor switch closed as shown in Fig. 1 the aspirator 18-19 whirls rapidly in the submerging liquid and draws air by entrainment from the airline pipe 15 and the radiator 10 until the vacuum tension sutlices to draw liquid up from the low-level cistern 16 into the chamber 38 by way of the supply pipe 47-49. Before the chamber 38 is entirely filled with liquid, the combined weight of the liquid and chamber sui'lices to overcome the resistance of the counterweight 39 with the result that the actuating lever turns about its fulcrum downward to the position indicated by dotted lines. Consequently, the switch blade 34 is made to open and stop the motor. The liquid in the chamber 38 will be held there by vacuum tension once open position ciently to allow the liquid to flow back into the low-level tank but, before the chamber is entirely emptied, the counterweight 39 will again over-balance the chamber and lever and cause the switch to close and restart the motor. The variations in vacuum tension required to effect these successive openings and closings of the switch depends largely on the size of the chamber 38 and the vertical distance through which it is allowed to move. It is found practicable to operate with a variation considerably less than is respresented by one inch of mercury. Fig. 1 represents to scale an ordinary vacuum heating system in which the distance from floor to ceiling is about nine feet and'the variation in vacuum tension ranges from about six to seven feet of water. 'In Figs.

1 and 4 the vertical pipes 15, 49 and 70'are shown interrupted on account of the enlarged scale. The elevation of the chamber 38 above the low-level cistern 16 determines the degree of vacuum tension that will be maintained. For

maintaining unusually high tension, mercury could be substituted for water in the low-level cistern. The liquid in the cistern absolutely prevents air leakage back into the system through the pipe 15. This aspirator requires submersion in liquid in order to operate, and therefore no extra cistern is required for operating themotor switch. In steam heating systems, the chance leakage of steam past the air valves on the radiators, which chance is almost sure to occur, serves a useful purpose in supplying the low-level cistern with enough water to compensate for the loss through evaporation. The system would} not fail to operateif the radiators were not supplied with air valves to prevent escape of steam, but steam would be wasted unless the amount'of steainentering the air line suction pipe is materially restricted. The

effectual provision against leakage of air disc of insulating material 58 interposed between two flanges 59 to which the inner ends of the shaft halves are secured. m line with I p l'w: pa-

each other asv shown in Fig. o. ripheries of the flanges 59 project beyond the insulating disc 58 so that their combinav tion form agrooved pulley. The axle 5'? has two bearing brackets 60 depending from an insulating grooved pul 61 so as toCOmewithin range of the switch blades 56 which are disposed to 'make'and break contact with the'contactors by giving the pulley 58-59 reciprocating rotation.

' Connected with'thei bearing brackets 60 are binding screws63 for wires leading to the source of electric current. The binding screws 64 establishconnection between the the motor 30. 1 The switch chamber 65 is similar "in construction to the chamber 88 but its upper head66 'ishung by-"a nonconducting cord 67 which winds aroundthe grooved pulley 58'-59 and is fastened thereto, A counterweight 68 is suspended by a .cord 69 which winds around and is fastened to thepulley 5859 in reverse direction to V the similar cord 67 so as to over-balance and lift the chamber-.65 when empty or not too;

The supply" heavily charged "with liquid. pipe 70 communicates with the bottom of the switchchamber 65 through a clamping nut 71 which has a reduced extension reaching through the lo wer head 72 into the chamberwhere it" screws on to the lower end of the clamping rod 7 3 whose upper end screws into the upper head 66. The .reduced extension of the nut-71 has a perforation 7 1 just above the upper surface of the lower head 72 through which liquid can enter into and escape from the chamber. The supply pipe 7 O, in this case, screws into and hangs directly down fromthe clamping nut 71 into the liquid in the low-level cistern 16, passing loosely through the cover 26 which serves as a guide. The flexible tubing 7 5 establishes communication between the upper end of the chamber 65 and the suction pipe 15 and is long enough to allow several inches vertical rise and fall of the chamber. The operation is essentially the same as in the previous described construction, but the supply pipe 70 does not require flexible connection, as the submerged end can rise and fall with the switch chamber of which it in reality forms a part. This modified form also has the advantage of greater compactness than that first described;

An additional feature is shown in Fig. 4: which is not absolutely essential but serves to insure a full sliding contact between the switch blades and contactors and a quick break when the blades are withdrawn. A retarding pin 76 which projects from one side of the switch pulley 58'59 meets and passes a yielding obstruction 77 flexibly depending from the insulating plate 61 during the final movement of rotation just be fore the descending chamber 65reaches its pitta 61 n eit er sideor the er? 8 5 J1 s" p m r-- tors 62 also depend from the insulating plate lowestposition ofdescentz- So,- bfore the j 1 reverseporfclosing movement, of the lswitch *can proceedbeyondabeginning the rota I tionof the pulley-is interrupted until the; supply "of liquid in i the chamber '65 is gtur-l a-moreiorcible clos-,

ther depleted, insurin m of the-switch: This'in'litseltwhen the I switch a-gain opens, insures a quick break, which may be still further accelerated by attachingthe switch blade 56 to the aXle 57 -by' fiexibleconnectioni: In Fig. 4,1thswitch bladejis represented as afpiece of thin elastic metal of considerable length bent and is secured to the axle 57 7 by; means of the set screw' 79. Ashoulderg'pinj80 inserted-into: the holding block, and" loosely piercingthe switch blade "limitstheoyielding movement side of the pulley 58-59limitsthe downward movement of-the counterweight 68 by comingin contact with the bearing bracket 60. The downward movement oftheswitch chamber 65 maybe limited by contact or low-level lines. 7 "I claim:

fastened to a holding block 7 8 Which-in turn upwardof the blade just'Zbefore the break 5 occurs. A stop pin 81-p rojectingfrom the- .85 i

no thesupply pipe 70 with the bottomof the I ciistern lti as indicated by dotted with-theradiators andtheair linefsuction I pipe leading from said radiators, of a 'low level cistern containing liquid, an. a'spirator submerged in said cistern, submerged connection between said aspiratorand said air line suction pipe, a motorfor actuating saidi aspirator, a motor switch for control of said motor, a switch chamber displaceabledowne ward when charged with liquid, 9, counterweight disposed to raise said chamber when liquid is discharged therefrom, operative connection between said chamber and said motor switch a supply pipe leading down from the bottom of said chamber intothe liquid of said lowlevel' cistern, flexible pipe connection between the top of said chamber; 7'

and said air-line suction pipeand'm'eans for restrictlng the passage otvapor and water V fromvsaid radiators into sa d'air-line suction Y pipe, substantially as herein set forth.

2. In a heatlng system, the combination with the radiators and the air-line-suction V pipe leading from said radiators, of a lowlevel cistern containing liquid, an aspirator' having submerged connection in said cistern with said'air-line suction pipe, a motor for actuating said aspirator, a motor switch for control of said motor, a switch chamberidisplaceable downward when charged with'liquid, a counterweight disposed to raise said chamber when 7 liquid is dischargedtherefi from, operative connection between' isaid hamber and said motorswitch, a} supply pipe leading down from the bottom of. said i chamber into the liquid-in said low-level cisl tern, flexible tube eonnection between the top of said chamber and said air-line suction pipe and means for restricting the passage of vapor and water from said radiators into said air-line suction pipe, substantially as herein set forth.

3. 1n heating system, the combination with the radiators and th air-line suction pipe leading from said radiators, or" a lowlevel cistern containing liquid, an aspirator having submerged connection in said cistern with said air-line suction pipe, 3, motor for actuating said aspirator, a motor switch for control of said motor, a switch chamber displaceable downward when charged with liquid, a counterweight disposed'to raise said chamber when liquid is discharged therefrom, operative connection between said chamber and said motor switch, a supply pipe leading down from the bottom of said chamber into the liquid in said lowlevel cistern and flexible tube connection between the top of said chamber and said airline suction pipe, substantially as herein set forth. v

4. In a vacuum system, the combination with the air-line suction pipe, of a low-level cistern containing liquid, an aspiiator having submerged onnection in said cistern with said suction pipe, a motor for actuating said aspirator, a motor switch for contwee 'trol of said motor, a switch chamber dislacea'ble downward when charged with iquid, a counterweight disposed to raise said chamber when liquid is discharged therefrom, operative connection between said chamber and said motor switch, a sup submerged connection between said aspi' rator and said suction pipe, a motor for actuating said aspirator, a motor switch for control of said motor, a switch chamber displaceable downward when charged with liquid, a counterweight disposed to raise said chamber when liquid is discharged therefrom, operable connection between said chamber and said motor, a supply pipe leading down from the bottom of said chamber into the liquid in saidlow-level cistern and flexible tube connection between the top of said chamber and said suction pipe, substantially as herein set forth.

THOMAS O. PERRY. 

